from __future__ import print_function
# Script Name	: portscanner.py
# Author		: Craig Richards
# Created		: 20 May 2013 
# Last Modified	: 
# Version		: 1.0

# Modifications	: 

# Description	: Port Scanner, you just pass the host and the ports

import optparse				# Import the module
from socket import *		# Import the module
from threading import *		# Import the module

screenLock = Semaphore(value=1)		# Prevent other threads from preceeding

def connScan(tgtHost, tgtPort):		# Start of the function
	try:
		connSkt = socket(AF_INET, SOCK_STREAM)	# Open a socket
		connSkt.connect((tgtHost, tgtPort))
		connSkt.send('')
		results=connSkt.recv(100)
		screenLock.acquire()		# Acquire the lock
		print('[+] %d/tcp open'% tgtPort)
		print('[+] ' + str(results))
	except:
		screenLock.acquire()
		print('[-] %d/tcp closed '% tgtPort)
	finally:
		screenLock.release()
		connSkt.close()
		
def portScan(tgtHost, tgtPorts):	# Start of the function
	try:
		tgtIP = gethostbyname(tgtHost)	# Get the IP from the hostname
	except:
		print("[-] Cannot resolve '%s': Unknown host"%tgtHost)
		return
	try:
		tgtName = gethostbyaddr(tgtIP)	# Get hostname from IP
		print('\n[+] Scan Results for: ' +tgtName[0])
	except:
		print('\n[+] Scan Results for: ' + tgtIP)
	setdefaulttimeout(1)
	for tgtPort in tgtPorts:	# Scan host and ports
		t = Thread(target=connScan, args=(tgtHost, int(tgtPort)))
		t.start()

def main():
	parser = optparse.OptionParser('usage %prog -H'+' <target host> -p <target port>')
	parser.add_option('-H', dest='tgtHost', type='string', help='specify target host')
	parser.add_option('-p', dest='tgtPort',type='string', help='specify target port[s] seperated by a comma')
	(options, args) = parser.parse_args()
	tgtHost = options.tgtHost
	tgtPorts = str(options.tgtPort).split(',')
	if (tgtHost == None) | (tgtPorts[0] == None):
		print(parser.usage)
		exit(0)
	portScan(tgtHost, tgtPorts)
if __name__ == '__main__':
	main()